UNIVERSITY OF BAHRAIN
CHEMISTRY 101
SECOND HOUR EXAMINATION
29th November, 2005
Examiners: Drs. Saeed, Osama, Saad,
Sadeq, Awatef, Reema, Layla
Saleem, Salim, A. Taha & Jameela
Time : 70 min.
Name ___________________________________
I.D. # ____________ Sec._________
Circle the letter of the one correct answer. A double page of foolscap paper is provided
for calculations but only the circled answers on this exam copy will be graded. Each
question is worth one(1) point. Check that your paper has (15) questions.
1 atm = 760 mmHg , K= C + 273.15, R = 0.0821 L.atm/K.mol
MULTIPLE CHOICE :
Q.1.
Write the net ionic equation between HF and Ca(OH)2.
a. HF(aq) + OH-(aq)  F-(aq) + H2O(l)
b. 2F-(aq) + Ca(OH)2(aq)  CaF2(aq) + 2OH-(aq)
c. H+(aq) + OH-(aq)
 H2O(l)
d. 2F-(aq) + Ca2+(aq)  CaF2(aq)
e. 2HF(aq) + Ca(OH)2(aq)  CaF2(aq) + 2H2O(l)
Q.2.
The net ionic equation of the precipitation reaction between Ba(NO3)2 and Na2SO4 is :
a) Ba2+(aq) + SO 24  (aq)  BaSO4(s)
b) Ba(NO3)2(aq) + Na2SO4(aq)  BaSO4(s) + 2NaNO3(aq)
c) 2NO 3 (aq) + Na2SO4(aq)  SO 24  (aq) 2NaNO3(aq)
d) Ba(NO3)2(aq) + SO 24  (aq)  BaSO4(s) + 2NO 3 (aq)
e) 2NO 3 (aq) + 2Na+(aq)  2NaNO3(aq)
Q.3.
1.338 g of an ionic compound containing hydroxide ion (OH-) is treated with excess of
Fe(NO3)3 solution. If the mass of precipitate [Fe(OH)3] formed was 1.96 g. What is the
percentage of oxygen (O) in the compound?
a. 19.4%
Fe3+(aq) + 3(OH-)(aq)  Fe(OH)3 (s)
b. 36.8%
c. 42.8%
d. 58.9%
e. 65.8%
Q.4.
What volume of 0.196 M of H2SO4 is needed to neutralize 54.4 ml of 0.3M of KOH?
H2SO4(aq) + 2KOH(aq)  K2SO4(aq) + 2H2O(l)
a. 25.3 ml
Q.5.
b. 13.6 ml
c. 35.4 ml
d. 8.3 ml
e. 41.6 ml
19.9 ml of NaOH solution was needed to neutralise 5.4 g of H3PO4.
3NaOH(aq) + H3PO4(aq)  Na3 PO4(aq) + 3H2O(l)
What is the molarity of NaOH?
a. 1.8 M
Q.6.
– 10.5C
b.
-20.3C
c.
5.5 C
d.
-147.1 C
e.
32.5 C
b. 0.52 atm
c. 0.93 atm
d. 2.63 atm
e. 4.60 atm
b. 8.62 g/L
c. 9.75 g/L
d. 6.67 g/L
e. 5.34 g/L
0.2 g of an unknown gas occupy 58 ml at 30C and 2.5 atm. Identify the gas.
a. H2S
Q.10.
e. 8.3 M
The density of a gas is 4.86 g/L at 5.37 atm. What will the density be at 5.9 atm? (Assuming
the temperature remains constant).
a. 12.30 g/L
Q.9.
d. 5.4 M
A gas sample was initially at -131.3 C and 480 mmHg was cooled to 23.4 C . What is its new
pressure? (volume and number of moles are constant)
a. 1.32 atm
Q.8.
c. 3.8 M
502 ml of a gas was heated to 150C so its final volume was 840 ml. What was its initial
temperature? (assuming the pressure and number of mole remain constant).
a.
Q.7.
b. 2.6 M
b. NO2
c. N2O
d. SO3
e. O3
Given :
2N2(g) + O2(g)  2N2O(g)
What volume of N2O(g) can be obtained from reaction of 30 L of N2 with 10 L of O2 ?(at the
same temperature and pressure)
a. 10 L
Q.11.
c. 20 L
d. 15 L
e. 25 L
Given the following equation:
CuSO4(aq) + 2NaOH(aq)  Na2SO4(aq) + Cu(OH)2(s)
What volume of 0.333 M CuSO4 solution will be required to react completely with 35.6 mL of
0.874 M NaOH?
a) 16.8 mL
Q.12.
b. 30 L
b) 20.6 mL
c) 26.7 mL
d) 28.9 mL
e) 46.7 mL
A sample of gas occupies a volume of 450 mL at 740 mmHg and -36.7C. What will be the
volume of the gas at STP?
a. 0.347 L
b. 0.388 L
c. 0.414 L
d. 0.506 L
e. 0.570 L
Q.13.
A 15.0 L vessel contains 190 g of CO2 gas. What is the pressure of the gas inside the vessel at
65.3C?
a. 5.0 atm
Q.14.
c. 7.0 atm
d. 8.0 atm
e. 9.0 atm
Given :
2KClO3(s)  2KCl(s) + 3O2(g)
If 10.9 g of KClO3 were decomposed, how many liters (L) of O2(g) can be collected at STP?
a. 0.800 L
Q.15.
b. 6.0 atm
b. 1.097 L
c. 3.00 L
d. 0.167 L
e. 0.500 L
A 5.71 g sample SX6(g) has a volume of 0.94 L at 1 atm and 217.5C. Identify X:
a. Cl
b. O
c. N
d. Br
e. F